JPH093122A - Production of postchlorinated vinyl chloride resin - Google Patents

Abstract

PURPOSE: To produce an easily gelling postchlorinated vinyl chloride resin by suspension-polymerizing a vinyl chloride monomer in the presence of a specified vinyl chloride copolymer having anionic or cationic hydrophilic groups as side chains and chlorinating the product. CONSTITUTION: A vinyl chloride monomer is suspended in an aqueous medium in the presence of a water-soluble polymer as a suspending agent and a vinyl chloride copolymer (DPVC) having 0.1-8wt.% anionic or cationic hydrophilic groups as side chains and having an average degree of polymerization of below 800 and polymerized by the use of a polymerization initiator soluble in the vinyl chloride monomer to make a vinyl chloride resin. This resin is chlorinated to make a postchlorinated vinyl chloride resin (CPVC). The DPVC is insoluble in water, is soluble in a vinyl chloride monomer and functions as a dispersion stabilizer. It is obtained for example by copolymerizing sodium vinylsulfonate with VC. The suspending agent is desirably a polymer such as polyvinylpyrrolidone. The CPVC can easily gel at low temperatures, is therefore easily process-able and can give moldings of excellent impact strength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a chlorinated vinyl chloride resin. In particular, the present invention relates to a method for producing a chlorinated vinyl chloride resin, which is characterized in that the obtained chlorinated vinyl chloride resin is easy to gel and is easy to process.

[0002]

2. Description of the Related Art Chlorinated vinyl chloride resin (hereinafter referred to as CPVC) is made by chlorinating vinyl chloride resin (hereinafter referred to as PVC). CPVC is PV
The property called C's advantage is left, and the property called a defect of PVC is improved. That is, CPV
C is an improved version of PVC's disadvantage of poor heat resistance, while retaining the excellent weather resistance, flame resistance, and chemical resistance of PVC. More specifically, PVC
Has a low heat distortion temperature and the usable upper limit temperature is 60 to 70.
Since it is around ℃, it cannot be used for hot water, but CPVC has a heat distortion temperature of 20 to 40 ℃ than PVC.
It is expensive and can be used with hot water. Therefore, CPVC is suitable for making heat resistant pipes, heat resistant joints, heat resistant valves and the like.

As mentioned above, CPVC has a higher heat distortion temperature than PVC. Therefore, in order to process CPVC into a molded body, it must be heated to a temperature higher than that of PVC to cause gelation. However, CPVC easily decomposes when heated to a high temperature, and therefore tends to decompose and become colored when it is heated and gelated. Therefore, CPVC is more difficult to gel by heating than PVC. Therefore, when a molded product is made from CPVC, the molded product is one in which CPVC is not sufficiently gelled. For this reason, CPVC molded products are PV
The result is that the impact strength is inferior to that of C. As a result, CPVC has become less available. Therefore, it has been desired to improve the gelling properties of CPVC so that it can be gelled by heating to a relatively low temperature.

Although we have not tried to improve the gelling properties of CPVC, we have tried to improve the gelling properties of PVC by using PV
In the suspension polymerization step of C, it is known to use partially saponified polyvinyl acetate or a modified product thereof as a suspending agent. For example, Japanese Patent Laid-Open No. 56-81317 discloses that a sulfuric acid ester, a phosphoric acid ester or a salt thereof is added to a side chain of 0.02
~ 5 mol%, saponification degree 60 ~ 80 mol%, average degree of polymerization 600 ~ 1500 modified polyvinyl alcohol and water-soluble cellulose derivative as a suspending agent to suspend vinyl chloride monomer It is described that when it is polymerized, the obtained PVC easily gels at low temperature. Also,
Japanese Examined Patent Publication (Kokoku) No. 57-37162 discloses that the side chain contains 0.01-5.
Using a modified polyvinyl alcohol having a saponification degree of 60 to 90 mol% containing a mol% of a hydrophobic group and 0.02 to 10 mol% of an anionic hydrophilic group as a dispersion stabilizer, a vinyl chloride monomer, etc. It is described that when the vinyl-based monomer is suspension-polymerized, a PVC that easily gels can be obtained.

However, the partially saponified polyvinyl alcohols described in these publications have a large saponification degree of 60 mol% or more. As a result, it is close in nature to polyvinyl alcohol and is therefore water-soluble. Therefore,
The term "modified polyvinyl alcohol" is used to describe this. Moreover, these publications only describe the production of PVC by suspension polymerization.
No further mention is made of what properties the resulting CPVC will exhibit upon further chlorination of C.

[0006]

DISCLOSURE OF THE INVENTION The present invention is intended to provide CPVC having good gelling properties. That is, according to the present invention, the excellent properties of PVC are retained as they are, and the gelling property is greatly improved. Therefore, it is possible to sufficiently gelate by heating to a relatively low temperature. It is intended to provide CPVC.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the inventor made an in-depth examination in the stage of manufacturing PVC. As a result, when PVC is produced, suspension polymerization is carried out using a special dispersion stabilizer, and the PVC thus obtained is chlorinated by a conventional method.
It was found that C tends to gel at low temperature. That is, in the suspension polymerization of PVC, various suspension agents have been used so far, but a water-soluble polymer is selected from them, and at the same time, a hydrophilic group is contained as a dispersion stabilizer. If a vinyl chloride copolymer is used, vinyl chloride monomer is subjected to suspension polymerization in the presence of these suspending agent and dispersion stabilizer to produce PVC, and this PVC is chlorinated to produce CPVC. It has been found that CPVC results in improved gelling properties. The vinyl chloride copolymer containing a hydrophilic group described above has an average degree of polymerization of 800 including an anionic hydrophilic group such as a sulfonic acid group in the side chain of the molecule.
PVC of less than, was not soluble in water but soluble in vinyl chloride monomer. Most of the suspension agents or dispersion stabilizers that have been used so far are soluble in water and not soluble in vinyl chloride monomer, but the above-mentioned dispersion stabilizers are soluble in vinyl chloride monomer. It is unique in that it does. The present invention has been developed on the basis of such knowledge.

The present invention has a side chain containing 0.1 to 8% by weight of an anionic hydrophilic group or a cationic hydrophilic group and has an average degree of polymerization of less than 800 in the presence of a vinyl chloride copolymer. , A water-soluble polymer is used as a suspending agent, a vinyl chloride monomer is suspended in an aqueous medium, a polymerization initiator that dissolves in the vinyl chloride monomer is added, and the vinyl chloride monomer is polymerized. The gist of the present invention is to provide a method for producing a chlorinated vinyl chloride-based resin, which is characterized in that a vinyl chloride-based resin is produced by the above process and then this vinyl chloride-based resin is chlorinated.

The present invention is roughly divided into two steps. The first step of them is a step of making PVC, and the second step is a step of chlorinating PVC to CPVC. This invention differs from conventional methods in the process of making PVC, and PVC made by a unique method
Is characterized in that it is used as a raw material for the subsequent chlorination step, and the chlorination step is no different from the conventional method.

Therefore, the manufacturing process of PVC according to the present invention will be described first. The manufacturing process of PVC generally follows the conventional suspension polymerization method. However, according to the present invention, when a vinyl chloride monomer (hereinafter, abbreviated as VC) is suspended in an aqueous medium, a water-soluble suspension agent that has been used as a suspension agent has been used. It is necessary to select and use a water-soluble polymer, and use a dispersion stabilizer that has never been used in the suspension polymerization of VC. The dispersion stabilizer is a vinyl chloride polymer containing 0.1 to 8% by weight of a hydrophilic group and having a low average degree of polymerization, but it has a low average degree of polymerization of less than 800 and therefore is soluble in water. It has the property of dissolving in VC without it. In this respect, the above dispersion stabilizer is unique.

In the present invention, the water-soluble polymer is used as the suspending agent as described above. So far, in suspension polymerization of VC, a high molecular weight substance and a low molecular weight substance have been broadly used as a suspending agent. The high molecular weight substance is, for example, polyvinylpyrrolidone, and the low molecular weight substance is, for example, glycerin monostearate. Of these, a low molecular weight substance has no particular effect even if used, and therefore a high molecular weight substance is selected and used in the present invention.

Polymers that can be used can be classified into cellulose derivatives and synthetic polymers, and it is sufficient to use at least one of them. As the cellulose derivative, methyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose, hydroxybutyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose or the like can be used. As the synthetic polymer, in addition to the above-mentioned polyvinylpyrrolidone, polyvinyl alcohol, partially saponified polyvinyl alcohol, vinyl acetate / maleic acid copolymer, polyacrylate, high molecular weight polyethylene glycol, polypropylene glycol, etc. may be used. it can. All of these are water-soluble suspension agents.

In the PVC manufacturing process of the present invention,
A dispersion stabilizer containing a vinyl chloride copolymer (hereinafter referred to as DPVC) having an average degree of polymerization of less than 800, which contains 0.1 to 8% by weight of an anionic hydrophilic group or a cationic hydrophilic group in the side chain. The most important feature is to use as. here,
A sulfonic acid group, a carboxyl group, a phosphoric acid group, a sulfuric acid group or the like can be used as the anionic hydrophilic group, and a quaternary ammonium salt group can be used as the cationic hydrophilic group.

In the present invention, DPVC used as a suspension stabilizer can be prepared by the following method. That is, it is a method of copolymerizing VC with a vinyl compound containing an anionic hydrophilic group or a cationic hydrophilic group. Specifically, taking a sulfonic acid group as the anionic hydrophilic group, for example, sodium vinyl sulfonate and VC are copolymerized to obtain a copolymer having an average polymerization degree of 600 containing 2 mol% of sodium vinyl sulfonate. It is a method of making a polymer.

In the above method, the following vinyl compounds can be used. First, in the case of introducing a sulfonic acid group, allylsulfonic acid, methacrylsulfonic acid, styrenesulfonic acid, vinylsulfonic acid, 2-acrylamido-2- Methyl propane sulfonic acid or the like can be used. Next, to introduce a carboxyl group, acrylic acid, methacrylic acid, succinic acid monoacryloyloxyethyl ester, phthalic acid monoacryloyloxyethyl ester, succinic acid monomethacryloyloxyethyl ester, and phthalic acid monocarboxylic acid are used as vinyl compounds. Having one carboxyl group in the molecule, such as methacryloyloxyethyl ester,
Those having a plurality of carboxyl groups in the molecule such as maleic acid and fumaric acid can be used. To introduce a phosphate group, acid phosphoxyethyl (meth) acrylate, acid phosphoxypropyl (meth) acrylate, 3-chloro-2-acid phosphoxypropyl (meth) acrylate or the like can be used as the vinyl compound. . To introduce a cationic hydrophilic group, methacrylamidopropyltrimethylammonium chloride, acrylamido-3-methylbutyltrimethylammonium chloride, diallyldimethylammonium chloride or the like can be used as the vinyl compound.

The above water-soluble polymer has a VC of 0.
It is suitable to use 005 to 0.2% by weight, and more preferably 0.01 to 0.1% by weight. Also, DPVC is 100 to 10,000 pp relative to VC
It is suitable to use m, of which 1000-800
It is more preferable to use it within the range of 0 ppm. The reason is that when the amount of DPVC present is in the range of 100 to 10,000 ppm, the processability of CPVC obtained from this is good, but when the amount of DPVC added is less than 100 ppm, DPVC is added. If the amount of DPVC added exceeds 10,000 ppm, the resulting PVC particles will become too large and the polymerization reaction will not proceed smoothly, and good results will be obtained. Because it will disappear.

The proportion of hydrophilic groups contained in DPVC is in the range of 0.1 to 8% by weight.
It is preferable to set it to ˜5% by weight. The above ratio is 0.1
The reason for setting the content to 8% by weight is that if the ratio of the hydrophilic group exceeds 8% by weight, DPVC becomes difficult to dissolve in VC and it becomes difficult to carry out suspension polymerization of VC, and conversely less than 0.1% by weight. Then, the effect of the hydrophilic group does not remarkably appear. Further, DPVC has an average degree of polymerization of less than 800, and the range of 100 to 600 is preferable among them. The reason why the average degree of polymerization is less than 800 is that the average degree of polymerization is 800.
If it exceeds, the effect of the degree of polymerization becomes strong and the effect of the hydrophilic group becomes difficult to appear.

As a method for obtaining DPVC, any of emulsion polymerization, bulk polymerization, suspension polymerization and solution polymerization may be used.
The solvent used in the solution polymerization includes n-hexane, methanol, ethanol and other lower alcohols, as well as ketones, esters and chlorinated hydrocarbons generally used in the solution polymerization.

In the PVC manufacturing process of the present invention,
An aqueous medium is used as the medium for carrying out the suspension polymerization.
Deionized water is preferred as the aqueous medium. The amount ratio of VC to the aqueous medium is not different from the range conventionally used, but it is suitable that the range is approximately 1 to 1 to 1: 3 by weight.

In the PVC manufacturing process of the present invention,
A polymerization initiator is used for carrying out suspension polymerization, but the polymerization initiator needs to be soluble in VC. As the polymerization initiator, those which have been used for suspension polymerization of VC can be used as they are. Examples are organic peroxides such as lauroyl peroxide, α-cumylperoxy neodecanoate, t-butylperoxy neodecanoate, and 2,2′-
An azo compound such as azobisisobutyronitrile. The amount used is no different from the conventional method.

The process for producing PVC according to the present invention is not limited to the case where only VC is used as a monomer, but is applicable to the case where a copolymer is prepared by mixing VC and another monomer. be able to. As other monomers, ethylene, propylene, vinyl acetate, alkyl vinyl ether, acrylic acid and its ester can be used.

The PVC production process in the present invention can be carried out in the same manner as the conventional suspension polymerization of VC, except that the above-mentioned special DPVC is used as the dispersion stabilizer. That is, an autoclave was used as a container, and an aqueous medium such as deionized water was first put in this container, and then a water-soluble polymer as a suspending agent and DPVC as a dispersion stabilizer were added and stirred, and then the inside of the autoclave was After degassing under reduced pressure to remove oxygen, and then VC was added to disperse the VC in an aqueous medium to form a suspension state,
A polymerization initiator is added to this. Then, the autoclave is heated to maintain the contents at a high temperature for several hours to carry out the polymerization of VC. V in the autoclave as polymerization progresses
When the pressure of C has dropped, the autoclave is cooled to lower the temperature of the contents, unreacted VC is recovered, and the contents are taken out. Thereafter, dehydration and drying are performed to obtain PVC.

In the present invention, the PVC obtained as described above is then chlorinated. The chlorination step can be performed by directly following the conventional method. That is, chlorination can be carried out in any of a state in which PVC is suspended, a state in which it is dissolved in a solvent, and a solid state. Chlorination is performed by contacting PVC with chlorine.

When chlorinating PVC in suspension,
Chlorination can be carried out by blowing chlorine directly into the suspension itself obtained by suspension polymerization without separating the PVC obtained by suspension polymerization from the aqueous medium.
In addition, after separating PVC from the above suspension,
Can be dispersed again in another aqueous medium, and chlorine can be blown into the dispersion for chlorination. At this time,
It is preferable to irradiate ultraviolet rays to promote chlorination.
Further, a small amount of ketones such as acetone and methyl ethyl ketone may be added to the aqueous medium, and if necessary, a small amount of chlorine-based solvent such as hydrochloric acid, trichloroethylene and carbon tetrachloride may be added.

In the chlorination step in the present invention, it is preferable that the CPVC obtained has a chlorine content of 60 to 70% by weight.

[0026]

According to the method of the present invention, a vinyl chloride copolymer having a side chain containing 0.1 to 8% by weight of an anionic hydrophilic group or a cationic hydrophilic group and an average degree of polymerization of less than 800 is used. Coupling, ie, in the presence of DPVC, using a water-soluble polymer as a suspending agent, suspending VC in an aqueous medium,
A polymerization initiator which dissolves in
Since C is added and then PVC is chlorinated, CPVC can be easily obtained without much difference from the conventional method, and the obtained CPVC is not only inferior to conventional CPVC, but also thermally stable. It has excellent properties and has a low gelling temperature, and therefore is easy to process, and in this respect, it is an improvement over the drawbacks of the conventional CPVC.

[0027]

[Examples] Hereinafter, the reason why the method of the present invention is excellent will be specifically described by giving Examples and Comparative Examples. In the examples and the comparative examples, “parts” simply means “parts by weight”. The physical properties of the obtained CPVC such as gelation temperature, thermal stability and heat distortion temperature are measured there, and the measuring method is as follows.

First, for the measurement of physical properties, a mixture having the following ratio was prepared. CPVC 100 parts Tribasic lead sulfate 3 Dibasic lead stearate 1 MBS resin 10 Gelation temperature Using a Plastmill R-90 manufactured by Haak, 55 g of the above-mentioned formulation was rotated at 40 rpm and the temperature was 150 ° C.
Kneading was performed while increasing the temperature at a rate of temperature increase of 5 ° C./min, and the temperature at which the kneading torque reached its peak was taken as the gelling temperature. Thermal Stability The above composition was fed to a kneader composed of two 8-inch rolls, kneaded at a surface temperature of the roll of 205 ° C., and the kneaded product was wound around the roll. While turning back the CPVC sheet wound every 30 seconds from the start of winding, a small amount of the sheet was cut out every 3 minutes to compare the coloring degree of the sheet, and the heat stability was shown in the time until it turned blackish brown. Heat distortion temperature The above mixture was supplied to a kneader composed of two 8-inch rolls and kneaded at 190 ° C for 3 minutes to obtain a sheet having a thickness of 0.5 mm. The sheets were stacked and press-molded at a temperature of 195 ° C. and a pressure of 150 kg / cm ² for 8 minutes to form a press plate having a thickness of 6.4 mm. Using this press plate as a test piece, the heat distortion temperature was measured under a load of 18.6 kg / cm ² according to ASTM D648.

[0029]

Example 1 In this example, partially saponified polyvinyl alcohol was used as a water-soluble polymer and hydroxymethyl cellulose was used in combination, and a dispersion stabilizer containing a phosphoric acid group as an anionic hydrophilic group in DPVC was used. (Production of DPVC, that is, PVC containing a phosphoric acid group in the side chain) DPVC was produced by adding a vinyl compound containing a phosphoric acid group to an autoclave which had been initially charged and copolymerizing the autoclave. Details are as follows. Initial charging 8100 g of methanol (first-grade reagent) and 25 g of α-cumylperoxyneodecanoate as a polymerization initiator were charged in a stainless steel autoclave with an internal volume of 20 L equipped with a stirrer, and then exhausted with an aspirator for 5 minutes to remain. Removed air. Next, 2600 g of vinyl chloride was charged. Post-addition Charge After removing air from a 3 L stainless steel container, a mixed solution of 259 g of 2-hydroxypropyl acrylate dissolved in 500 g of methanol and 15 g of acid phosphoxyethyl methacrylate was sucked, and then 1045 g of vinyl chloride was injected under pressure. After shaking the container to mix and dissolve the contents, a flexible tube was used from the valve at the bottom to connect to the addition nozzle of the autoclave. Polymerization reaction operation The rotation speed of the stirrer of the autoclave was set to 380 rpm,
Hot water was passed through the jacket to raise the internal temperature to 43 ° C. Four
When the temperature reaches 3 ° C, add 50 parts of the mixed monomer solution from the addition container.
g, then 4 every 5 minutes depending on the progress of the polymerization reaction.
6g x 4 times, 31g every 10 minutes x 8 times, 27g every 5 minutes
× 49 divided times and added. 1 after the last addition
After 0 minutes, the polymerization reaction was stopped by cooling to 25 ° C. After cooling, the unreacted vinyl chloride was discharged as an exhaust gas, and then the vinyl chloride was sufficiently removed by passing nitrogen gas. Then, the methanol slurry of the copolymer was extracted from the autoclave, filtered, and then vacuum dried at 50 ° C. for 24 hours. 1300 g of a white powdery granular copolymer was obtained. The degree of polymerization of the resin is 33
0, the composition was vinyl chloride 86.5%, 2-hydroxypropyl acrylate 12.9%, and acid phosphoxyethyl methacrylate 0.6%. (Production of PVC) In this example, a partially saponified polyvinyl alcohol (PVA) and hydroxypropylmethyl cellulose were used as a suspending agent composed of a water-soluble polymer, and a polycation containing a side chain containing an anionic hydrophilic group. The DPVC obtained above was used as the vinyl chloride polymer. The details of the implementation are as follows. In a polymerization vessel having an internal volume of 216 liters, 143 parts of deionized water and a saponification degree of 72 as a suspension agent
Mol% partially saponified PVA 0.05 parts by weight and hydroxypropylmethyl cellulose 0.02 parts by weight and DP
After adding 0.01 part by weight of VC and removing oxygen in the polymerization vessel under reduced pressure, 100 parts by weight of vinyl chloride monomer and 0.017 part by weight of α-cumylperoxyneodecanoate as a polymerization catalyst, 0.06 parts by weight of t-butyl peroxy neodecanoate was added. Then, the polymerizer 58
Polymerization was carried out while maintaining the temperature at ℃, and the internal pressure of the polymerization vessel was 7.0.
When the amount reached kg / cm ² , unreacted vinyl chloride monomer was recovered, the contents were taken out, and dehydrated and dried. The polymerization yield of this vinyl chloride resin is 85%, and the average degree of polymerization is 100.
It was 0. (Production of CPVC) 500 parts by weight of deionized water and 100 parts by weight of the above vinyl chloride polymer were placed in a glass-lined reaction tank having an inner volume of 300 liters, and the vinyl chloride polymer was dispersed in water by stirring. The reaction tank was heated to maintain the temperature inside the tank at 70 ° C. Next, after blowing nitrogen gas into the reaction tank and replacing the inside of the tank with nitrogen gas, chlorine gas was blown in, and the vinyl chloride polymer was chlorinated while irradiating the inside of the tank with ultraviolet rays using a mercury lamp. The concentration of hydrochloric acid in the tank was measured to examine the progress of the chlorination reaction, and when the chlorine content of the obtained chlorinated vinyl chloride resin reached about 68.5% by weight, the supply of chlorine gas was stopped. The chlorination reaction was completed. After that, unreacted chlorine was removed by blowing nitrogen gas into the tank, the resulting dispersion was neutralized with sodium hydroxide, washed with water, dehydrated, and then dried to obtain powdered chlorinated vinyl chloride resin. (CPVC) was obtained. The obtained CPVC has a chlorine content of 68.5% by weight and a gelation temperature of 190.
C., thermal stability was 25 minutes, and heat distortion temperature was 140.degree. This CPVC had a lower gelation temperature and was easier to process than the CPVC of Comparative Example 1 described later.

[0030]

Comparative Example 1 The procedure of Example 1 was repeated, except that the polyvinyl chloride polymer as the dispersion stabilizer was not used.

The chlorine content of the obtained CPVC is 68.5.
% By weight, gelling temperature was 200 ° C., thermal stability was 24 minutes, heat distortion temperature was 138 ° C.

Comparing the CPVC obtained in Example 1 with the CPVC obtained in Comparative Example 1, both of them showed a polyvinyl chloride polymer having an anionic hydrophilic group in the side chain in the PVC production process. The only difference was whether or not they were used, the chlorine content was the same 68.5% by weight, the heat distortion temperatures were approximately the same values of 140 ° C and 138 ° C, respectively, and the thermal stability was 25 minutes. Although it does not change much in 24 minutes, both are 190 ° C at the gelling temperature.
And 200 ° C, a difference of 10 ° C. From this, it becomes clear that the effect of the polyvinyl chloride polymer having an anionic hydrophilic group in its side chain is remarkable.

[0033]

Example 2 In the production of CPVC of Example 1, CP
The same operation as in Example 1 was performed except that the supply of chlorine gas was stopped when the chlorine content of VC reached 66.5% by weight.

Therefore, in this example, the chlorine content of CPVC was 66.5% by weight. The gelling temperature of this CPVC was 172 ° C., the thermal stability was 20 minutes, and the heat distortion temperature was 104 ° C. This CPVC had a low gelation temperature and was easy to process as compared with the CPVC obtained in Comparative Example 2 below.

[0035]

Comparative Example 2 The procedure of Example 2 was repeated, except that the polyvinyl chloride polymer containing an anionic hydrophilic group in the side chain was not used.

Therefore, the chlorine content of the obtained CPVC is 66.5% by weight. The gelling temperature of this CPVC is 1
The temperature was 88 ° C, the thermal stability was 21 minutes, and the heat distortion temperature was 104 ° C.

Comparing the CPVC obtained in Example 2 with the CPVC obtained in Comparative Example 2, whether they used a polyvinyl chloride polymer having an anionic hydrophilic group in the side chain in the production process. The only difference is that the chlorine content is 66.5% by weight, the heat distortion temperature is 104 ° C., and the thermal stability is 20%.
The gelation temperatures are 172 ° C. and 188 ° C., which are almost the same value as minutes and 21 minutes, showing a large difference reaching 16 ° C. From this, it is clearly recognized that the effect of the polyvinyl chloride-based polymer having an anionic hydrophilic group in its side chain is remarkable.

[0038]

Example 3 In this example, as a polyvinyl chloride polymer containing an anionic hydrophilic group in the side chain, a polymerization degree of 400, vinyl chloride 83% by weight, 2-hydroxypropyl acrylate 15% by weight, hydrophilic 2-acrylamido-2-methylpropanesulfonic acid sodium salt 2 as a group
The thing containing the weight% was used. Specifically, in Example 1, the amount of partially saponified PVA was set to 0.04 part, the amount of hydroxymethyl cellulose was set to 0.02 part, and a polyvinyl chloride system containing an anionic hydrophilic group in the above side chain was used. The procedure of Example 1 was repeated except that 0.02 part of the polymer was used.

The CPVC obtained has a chlorine content of 68.5% by weight, the gelling temperature is 188 ° C.,
The thermal stability was 28 minutes and the heat distortion temperature was 140 ° C. This CPVC is the CPVC obtained in Comparative Example 1 above.
Compared with, the gelling temperature was low and it was easy to process.

[0040]

Example 4 In this example, a polyvinyl chloride-based polymer having an anionic hydrophilic group in its side chain was used as a polyvinyl chloride-based polymer having a polymerization degree of 600, vinyl chloride 73% by weight, 2-hydroxypropyl acrylate 5% by weight, and n. -Butyl acrylate 1
The one containing 5% by weight and 7% by weight of sodium 2-acrylamido-2-methylpropanesulfonate as a hydrophilic group was used. Specifically, in Example 1, the amount of partially saponified PVA was 0.04 part, the amount of hydroxymethyl cellulose was 0.03 part, and a polyvinyl chloride system containing an anionic hydrophilic group in the above side chain. The procedure of Example 1 was repeated except that 0.01 part of the polymer was used.

The CPVC obtained has a chlorine content of 68.5% by weight, the gelling temperature is 180 ° C.,
The thermal stability was 24 minutes and the heat distortion temperature was 138 ° C. This CPVC had a low gelation temperature among the CPVCs having the above-mentioned chlorine content and heat distortion temperature, and was easy to process.

[0042]

Example 5 In this example, as a polyvinyl chloride polymer having a cationic hydrophilic group in its side chain, a polymerization degree of 300, vinyl chloride 77% by weight, 2-hydroxypropyl acrylate 15% by weight, hydrophilic As a group, one containing 8% by weight of acrylamido-3-methylbutyltrimethylammonium chloride was used. Specifically, in Example 1, the amount of partially saponified PVA was set to 0.06 part, hydroxymethyl cellulose was not used, and the polyvinyl chloride-based polymer containing a cationic hydrophilic group in the side chain was added to 0. The same procedure as in Example 1 was carried out except that 0.05 part was used.

The CPVC obtained has a chlorine content of 68.5% by weight, the gelling temperature is 184 ° C.,
The thermal stability was 26 minutes and the heat distortion temperature was 138 ° C. This CPVC had a low gelation temperature among the CPVCs having the above-mentioned chlorine content and heat distortion temperature, and was easy to process.

[0044]

Example 6 A suspension polymerization method was used as a DPVC polymerization method. That is, in a 20 L stainless steel autoclave with a jacket equipped with a stirrer, ion-exchanged water 9
200 g, 12.5 g of t-butylperoxy-2-ethylhexanoate and 100 g of polypropylene oxide-polyethyleneimine copolymer as a dispersant were supplied, the polymerization vessel was closed to eliminate air, and then vinyl chloride 4500 was added.
g was pressed in. Then, 10% by weight of a post-addition composition comprising 2400 g of vinyl chloride, 800 g of 2-hydroxypropyl acrylate and 100 g of 2-acryloyloxyethyl phthalic acid was press-fitted. The temperature was raised to 80 ° C. with stirring, and immediately after the temperature in the polymerization vessel reached 80 ° C., the rest of the post-addition composition was divided into 120 parts and added every 2 minutes to carry out suspension polymerization. It was Ten minutes after the last addition, the polymerization reaction was stopped by cooling to 25 ° C. After cooling,
Unreacted vinyl chloride and the like were removed, a polymerization slurry was taken out, washed with ion-exchanged water, and vacuum dried at 50 ° C. for 24 hours to obtain a white powdery granular copolymer. The degree of polymerization of the resin is 390, the composition is vinyl chloride 84%, 2-
It was 15.0% of hydroxypropyl acrylate and 1.0% of 2-acryloyloxyethyl phthalic acid.

The procedure of Example 1 was repeated, except that the amount of DPVC was 0.03 part, the amount of partially saponified PVA was 0.08 part, and that hydroxymethyl cellulose was not used. The obtained CPVC is 68.5% by weight.
The gelation temperature was 186 ° C., the thermal stability was 26 minutes, and the heat distortion temperature was 140 ° C. This CPVC is the CPVC obtained in Comparative Example 1 above.
Compared with, the gelling temperature was low and it was easy to process.

[0046]

Example 7 In this example, polymerization was carried out in batch instead of the initial charging and the post-addition charging as in Example 1. That is, 20L with a jacket equipped with a stirrer
Deionized water 9200 in the stainless steel autoclave
g, t-butylperoxy-2-ethylhexanoate 12.5 g, polypropylene oxide-polyethyleneimine copolymer 100 g as a dispersant were supplied, and after closing the polymerization vessel to eliminate air, vinyl chloride 6900 g, 780 g of vinyl acetate and 200 g of maleic acid were press-fitted. The temperature was raised to 80 ° C. with stirring, polymerization was performed for a predetermined time, and then the temperature was cooled to 25 ° C. to stop the polymerization reaction. After cooling,
Unreacted vinyl chloride and the like were removed, a polymerization slurry was taken out, washed with ion-exchanged water, and vacuum dried at 50 ° C. for 24 hours to obtain a white powdery granular copolymer. The degree of polymerization of the resin was 400, the composition was 88% vinyl chloride, 10% vinyl acetate, and 2.0% maleic acid.

The same procedure as in Example 1 was carried out except that 0.05 part of this DPVC and 0.06 part of the partially saponified PVA were used, and that hydroxymethyl cellulose was not used. The obtained CPVC is 68.5% by weight.
The gelation temperature was 185 ° C, the thermal stability was 25 minutes, and the heat distortion temperature was 140 ° C. The CPVC had a lower gelation temperature and was easier to process than the CPVC having the chlorine content and the heat distortion temperature as described above.

[0048]

[Comparative Example 3] In Example 1, a polyvinyl chloride-based polymer having an anionic hydrophilic group in its side chain had a polymerization degree of 1
000, 90% by weight of vinyl chloride, and 0.05 part of 10% by weight of sodium 2-acrylamido-2-methylpropanesulfonate as a hydrophilic group were used, and the same procedure as in Example 1 was carried out.

The CPVC obtained had a chlorine content of 68.5% by weight, a gelation temperature of 197 ° C., a thermal stability of 25 minutes and a heat distortion temperature of 138 ° C. This CP
VC had a higher gelation temperature than any of the CPVCs obtained in the examples.

Claims (2)

[Claims] 1. A side chain containing 0.1 to 8% by weight of an anionic hydrophilic group or a cationic hydrophilic group and having an average degree of polymerization of 8
Polymerization in which a water-soluble polymer is used as a suspending agent, a vinyl chloride monomer is suspended in an aqueous medium in the presence of a vinyl chloride-based copolymer of less than 00, and dissolved in the vinyl chloride monomer. A method for producing a chlorinated vinyl chloride resin, which comprises adding an initiator, polymerizing a vinyl chloride monomer to produce a vinyl chloride resin, and then chlorinating the vinyl chloride resin. 2. The anionic hydrophilic group is selected from the group consisting of a sulfonic acid group, a carboxyl group, a phosphoric acid group and a sulfuric acid group, and the cationic hydrophilic group is a quaternary ammonium salt group. The method of claim 1, wherein